You are probably right. I haven't seen any DHCP setting in my Wifi Extender. I I think the it just replicates all the superhub DHCP settings to Wifi Extender when it's on "access point mode".
I was having issue with WiFi extender being on as "WiFi extender" mode but after changing it to "access point mode" the connection is fine for all the devices. .
If that make sense?.